I am not so good at VC++(I had worked on it some 5 yrs back - VC++ 4;)), so I am trying to give you some info on it, but can't test it myself here as I dont have VC installed in mine.
See here is what MS says on "PRB: Unrecognized Database Format Error with Access 2000 Database"
You can also see this link, should be of some help.
(Also you can find a link to MS site KB article there in)
Hope that Helps.